In power converter circuits like boost or buck converter circuits it is common practice to use a valley-switching method or a zero voltage switching method to reduce switching losses in the circuit. Furthermore, it is known to use an extended zero voltage switching operation according to which a conduction time of a rectifier in the circuit is extended beyond zero current condition in the inductor to compensate the parasitic capacitance of the switches. This can be achieved by an extended conduction time of the synchronous rectifier switch in the circuit. However, there are still remaining switching losses which cannot be fully avoided. These problems in particular occur in high voltage power converters.